The present invention relates to a display apparatus for a navigational aid for displaying navigational information on a pusher boat carrying barges, for example.
Conventionally, when conveying barges from one port to another, several unpowered barges are often lashed together in an assembly and this barge assembly is pushed by a pusher boat which is coupled to the assembly.
To aid in navigation of a pusher boat carrying a barge assembly of this kind, a radar system has usually been used, in which a radar indicator presented an own ship mark representing the shape and the heading of the pusher boat at a sweep center (own ship position) together with a mark resembling the shape of the barge assembly.
FIG. 8 shows an example of an own ship mark and a mark representing the shape of a barge assembly presented on a screen of a conventional radar system, in which xe2x80x9cSxe2x80x9d designates the own ship mark and xe2x80x9cBxe2x80x9d designates the mark of the barge assembly. While a small rectangular area shown by broken lines represents the size of one individual barge, no indication of individual barges of this form has actually been provided in the conventional system.
In actual situations of transportation, however, one barge indicated by the broken lines may be removed from the barge assembly shown in FIG. 8 at one site and the barge assembly consisting of the remaining barges could be pushed together to a next site. One problem of the conventional radar system, or other navigational aid display apparatus, is that the on-screen barge assembly mark does not exactly represent the shape of the barge assembly in such cases, making it impossible for a navigator to recognize the correct shape of the barge assembly being transported on the screen, which also displays situations surrounding the own ship. Thus, there has still been a room for improvement in the conventional system to be used as a navigational aid for enhancing safety and efficiency in transporting barge assemblies.
Accordingly, it is an object of the invention to provide a navigational aid display apparatus which makes it possible to set and display a mark of a barge assembly correctly representing its shape, thereby overcoming the aforementioned problem of the prior art.
In one aspect of the invention, a display apparatus for a navigational aid for displaying an own ship mark and a barge assembly mark representing respectively the shapes of own ship and a barge assembly, which are coupled to each other, together with an image produced by the navigational aid indicating the position of own ship and her surrounding situations comprises means for displaying boundaries of adjacent barges constituting the barge assembly, and means for displaying a mark indicating the presence or absence of a barge at each location within the barge assembly mark according to a signal fed from an input terminal.
In another aspect of the invention, a display apparatus for a navigational aid for a navigational aid for displaying an own ship mark and a barge assembly mark representing respectively the shapes of own ship and a barge assembly, which are coupled to each other, together with an image produced by the navigational aid indicating the position of own ship and her surrounding situations comprises means for displaying boundaries of adjacent barges constituting the barge assembly, means for reading information on a choice of a location within the barge assembly mark entered by an operator using a pointer indicating the location of a desired barge, and means for displaying a mark indicating the presence or absence of a barge at the location selected by the operator.
In still another aspect of the invention, a display apparatus for a navigational aid for displaying an own ship mark and a barge assembly mark representing respectively the shapes of own ship and a barge assembly, which are coupled to each other, together with an image produced by the navigational aid indicating the position of own ship and her surrounding situations comprises means for reading numeric values or symbols on a pattern of the barge assembly or the locations of individual barges constituting the barge assembly, and means for displaying the pattern of the barge assembly, or a mark indicating the presence or absence of a barge at each location within the barge assembly mark according to the read numeric values or symbols.
In yet another aspect of the invention, a display apparatus for a navigational aid for displaying an own ship mark and a barge assembly mark representing respectively the shapes of own ship and a barge assembly, which are coupled to each other, together with an image produced by the navigational aid indicating the position of own ship and her surrounding situations comprises keys arranged in conformity with the arrangement of individual barges of the barge assembly, and means for reading operator inputs entered via the keys and displaying a mark indicating the presence or absence of a barge at each location within the barge assembly mark.
The navigational aid display apparatus thus constructed enables the operator to set the shape of the barge assembly mark, which is displayed on a screen of the navigational aid together with the own ship mark, to match the shape of the actual barge assembly.
In one form of the invention, the image produced by the navigational aid is an image of target echoes detected by radar installed on the own ship (e.g., pusher boat). This means that the display apparatus for the navigational aid of the invention superimposes the own ship mark and the barge assembly mark representing respectively the shapes of the own ship and the barge assembly pushed by the own ship on a radar image. This enables the operator to recognize the own ship position and her surrounding situations from the radar image as well as relationship between the own ship and the barge assembly.
In another aspect of the invention, a display apparatus for a navigational aid for displaying an own ship mark and a barge assembly mark representing respectively the shapes of own ship and a barge assembly, which are coupled to each other, together with an image provided by the navigational aid indicating the position of own ship and her surrounding situations comprises means for inputting a shape modification signal, means for generating based on the shape modification signal a signal representing the shape of the barge assembly newly formed, and means for displaying the outer shape mark of the barge assembly based on the signal from said signal generating means.
In yet another aspect of the invention, a radar apparatus for displaying an own ship mark and a barge assembly mark representing respectively the shapes of own ship and a barge assembly, which are coupled to each other, together with radar echo signals comprises means for inputting a shape modification signal, means for generating based on the shape modification signal a signal representing the shape of the barge assembly newly formed, and means for displaying the outer shape mark of the barge assembly based on the signal from said signal generating means.
In yet another aspect of the invention, a radar apparatus for transmitting radio signals and receiving echo signals by means of an antenna to search conditions around the own ship and for displaying on an indicator a mark representative of the size of own ship and a mark representative of the shape of a barge assembly coupled to the ship together with the surrounding conditions, said radar apparatus comprising an analog-to digital converter for converting echo signals received by said antenna into digital signals, a memory for storing the digital signals from said analog-to-digital converter, a signal processing circuit for converting the signals from said analog-to-digital converter from a polar coordinate system into a Cartesian coordinate system, a first display memory for storing the resultant converted signals from said signal processing circuit, an input terminal for producing a control signal to vary the shape of a barge assembly, a data processing circuit for producing mark signals for displaying a mark representative of a shape of a barge assembly in response to the control signal, a second display memory for storing the mark signals from said data processing circuit and the mark signals for displaying a mark representative of the own ship, and a display control circuit for displaying on said indicator the mark representative of the own ship and the mark representative of a shape of a barge assembly with radar images based on the signals from said first display memory and said second display memory.
According to the invention, it is possible to display the barge assembly mark in any shape matching the shape of the actual barge assembly together with an image produced by the navigational aid indicating the surrounding situations of own ship. This allows the operator to correctly recognize the shape of the actual barge assembly being transported, thereby assisting in enhancing the safety of the barge assembly and the efficiency of its transportation.
In particular, when the boundaries between adjacent barges constituting a barge assembly are displayed and the location of each desired barge is specified by means of the pointer, it is possible to easily set the pattern of any given barge assembly.
Furthermore, if an arrangement is made to set the pattern of the barge assembly by entering numeric values or symbols through a keyboard, it is possible to easily set the pattern of any given barge assembly.
Moreover, if an arrangement is made to set the presence or absence of a barge at each location within the barge assembly mark by using an input device including keys, for instance, arranged in conformity with the arrangement of individual barges of the barge assembly, it is easy for the operator to recognize the correspondence between the positions of the individual keys and the locations of the barges and to set the pattern of any given barge assembly.